Chemical, Physical, and Mechanical Characterization of Isocyanate Cross-linked Amine-Modified Silica Aerogels
We describe a new mechanically strong lightweight porous composite material obtained by encapsulating the skeletal framework of amine-modified silica aerogels with polyurea. The conformal polymer coating preserves the mesoporous structure of the underlying silica framework and the thermal conductivity remains low at 0.041 + or - 0.001 W m-1k-1. The potential of the new cross-linked silica aerogels for load-carrying applications was determined through characterization of their mechanical behavior under compression, three-point bending and dynamic mechanical analysis (DMA). A primary glass transition temperature of 130 C was identified through SMA. At room temperature, result indication a hyperfoam behavior where in compression cross-lined aerogels are lineary elastic under small strains<4% and then exhibit yield behavior (until 40% strain) follwed by densification and inelastic hardening.
K. Atul et al., "Chemical, Physical, and Mechanical Characterization of Isocyanate Cross-linked Amine-Modified Silica Aerogels," Chemsitry of Materials, American Chemical Society (ACS), Jan 2006.
The definitive version is available at http://dx.doi.org/10.1021/cm0513841
Mechanical and Aerospace Engineering
Keywords and Phrases
Amine-Modified Silica Aerogels; Mesoporous Structure; Polyurea; Silica Framework
Article - Journal
© 2006 American Chemical Society (ACS), All rights reserved.